Humidity is way too high, 70 rh will close stomata and limit photosynthesis greatly, containers are far too massive for such small seedlings fairly sure you transplanted, use biodegrabable pots that can be upsized with no pot replacement this is not optimal for autos as transplant recovery takes serious time out of growth. The tiny plants will need to gather what little water they can before gravity sucks it all away,water often but in smaller doses, reduce humidity, get lights closer to plants to achieve top of canopy temperatures of 85 farenheight, this will allow for optimal photosynthesis to occur within the leaf. Which In turn will suck up more water, but unless you get that humidity under control nothing will make it grow.